package org.example.msmservice.utils;

import java.text.DecimalFormat;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Random;

public class RandomUtil {
    private  static  final Random random=new Random();
    private static final DecimalFormat fourdf=new DecimalFormat("0000");
    private static final DecimalFormat sixdf=new DecimalFormat("000000");
    //获取随机数
    public  static String getFourRandom(){
        return  fourdf.format(random.nextInt(10000));

    }

    public static String getSixBitRandom() {
        return sixdf.format(random.nextInt(1000000));

    }
    //给定数组，抽取n个数据
    public static ArrayList getRandom(List list, int n){
        Random random=new Random();
        HashMap<Object,Object> hashMap=new HashMap<Object,Object>();
        for(int i=0;i<list.size();i++){
            int number=random.nextInt(100)+1;
            hashMap.put(number,i);
        }
        Object[] robjs=hashMap.values().toArray();
        ArrayList r=new ArrayList<>();
        for(int i=0;i<n;i++){
            r.add(list.get((int)robjs[i]));
            System.out.print(list.get((int) robjs[i]) + "\t");


        }
        System.out.print("\n");
        return r;
    }

}
